TOPIC:

1981 KZ440 LTD

Completely cleaned the carbs also replaced ALL jets. The carbs were a total mess. So much gunk in there so I thoroughly cleaned them and replaced pilots and mains with new. Popped off the top and cleaned diaphragms also. Have not done a carb sync because I don't own proper tools to do so. While I had the carbs off waiting on pilots to be ordered I did an oil change( not sure if that should be considered). Bike was running before carb cleaning but not well due to nasty carb. Carbs ARE getting gas and plugs look a little wet. WHATS NEXT ??

Did you check the fuel level using the clear tube method?

Did you perform a bench synchronization before installing the carbs?

Are you sure that the plug wires did not get mixed up? (This does not apply to twin cylinder models, sorry)

Are you sure that the kill switch is in the run position?

Are you certain that the carbs are tightly sealed in the intake manifolds and that the manifolds are not cracked and that they seal well against the engine?

Is the factory airbox and filter hooked up?

Do you have a genuine Kawasaki Factory Service Manual?

Why did you replace the jets? That may be an issue if the replacements aren't he same as the originals. Jets don't wear out. If they are dirty they should be cleaned, but that's about all you need to do UNLESS you removed the stock airbox or did some other modification that requires different jetting. Do you have the stock airbox on the bike? Did you change anything else while you were working on it? Is it possible that you put the floats in upside down? Ed

TexasKZ...

I did not use clear tube method. I did not sync carbs. Plug wires shouldn't be mixed up because there was never a point when they could of got switched. Kill switch is in run. All the boots seem to have nice seal. I currently only have half the factory air box but I'm working on getting missing parts. I don't have a manual I just use kz400.com

650ed wrote: Why did you replace the jets? That may be an issue if the replacements aren't he same as the originals. Jets don't wear out. If they are dirty they should be cleaned, but that's about all you need to do UNLESS you removed the stock airbox or did some other modification that requires different jetting. Do you have the stock airbox on the bike? Did you change anything else while you were working on it? Is it possible that you put the floats in upside down? Ed

I replaced the jets because I completely destroyed one trying to remove it because they were corroded in there and seemed like they haven't been cleaned or removed in a decade. So I figured if I'm changing one then might as well change em all. They are all genuine parts. Stock air box is half there. Floats should be right side up but might go back and check. I previously checked my valve clearances but I can't remember if that was before or after I took the carbs out for cleaning.

Half an air box is likely contributing to the problem. It may not be the entire problem, but the carbs were designed to be used with an air box. If the filter is missing you will have a lean condition.

When starting the bike cold you should have the choke on, kill switch in RUN, petcock on PRI (if vacuum type), fully charged battery, and do not touch the throttle. If the battery is not fully charged put it on a charger at 2 amp or LESS until it is fully charged. DO NOT try to jump start the bike from a running vehicle or charger. Ed

I think it would be a good idea to check the fuel level while the carbs are still in the bike. The clear tube method is clearly described in the fsm, and has been posted here numerous times. Give the search box a try. If the fuel level is really high in one or both carbs, it or they may be flooding. If way too low, the engine may not be able to pull any fuel in.

Bench synchronizing does not require anything fancier than a screwdriver and a paper clip. It is no substitute for proper synchronization, but will get the carbs close enough for the engine to start.

650ed wrote: Half an air box is likely contributing to the problem. It may not be the entire problem, but the carbs were designed to be used with an air box. If the filter is missing you will have a lean condition.

When starting the bike cold you should have the choke on, kill switch in RUN, petcock on PRI (if vacuum type), fully charged battery, and do not touch the throttle. If the battery is not fully charged put it on a charger at 2 amp or LESS until it is fully charged. DO NOT try to jump start the bike from a running vehicle or charger. Ed

I know the half air box isn't great I'm just waiting to hear back from a guy who has the parts for sale. But wouldn't it still start even without the air box ? Or is there too much air flow ? Should I possibly try restricting more air flow will that help suck in fuel ?

TexasKZ wrote: I think it would be a good idea to check the fuel level while the carbs are still in the bike. The clear tube method is clearly described in the fsm, and has been posted here numerous times. Give the search box a try. If the fuel level is really high in one or both carbs, it or they may be flooding. If way too low, the engine may not be able to pull any fuel in.

Bench synchronizing does not require anything fancier than a screwdriver and a paper clip. It is no substitute for proper synchronization, but will get the carbs close enough for the engine to start.

Ok thanks I'll try to find instruction on both and I'll give it a try

Lmmduramax wrote:
I know the half air box isn't great I'm just waiting to hear back from a guy who has the parts for sale. But wouldn't it still start even without the air box ? Or is there too much air flow ? Should I possibly try restricting more air flow will that help suck in fuel ?

Can you please post an image of the 1/2 airbox set up.

chconger wrote:
Can you please post an image of the 1/2 airbox set up.

I'm missing the factory filter / intake part. Usually I have a foam filter over the open part but I took it off to show a better picture

Sooooo I got it running .....

No idea what it was. I pulled carbs out again, popped off bowls to take a look to make sure everything was in place. Everything looked as it should. Put them back in and BANG it fired up with a roar!!

But now another problem has arised. It seems to back fire right out the carbs ! Backfires out the carbs with a little puff of smoke . What could be causing this ?